IBM System x3650 M4 56
The ServeRAID M5225 SAS/SATA Controller has the following specifications:
Eight external 12 Gbps SAS/SATA ports
Supports 12, 6, and 3 Gbps SAS and 6 and 3 Gbps SATA data transfer rates 
Two external x4 mini-SAS HD connectors (SFF-8644)
Supports 2 GB flash-backed cache (standard)
Supports RAID levels 0, 1, 5, 10, and 50 (standard)
Supports RAID 6 and 60 with the optional M5200 Series RAID 6 Upgrade
Supports optional M5200 Series Performance Accelerator and SSD Caching upgrades
PCIe x8 Gen 3 host interface
Based on the LSI SAS3108 12 Gbps ROC controller
Supports connectivity to the EXP2512 and EXP2524 storage expansion enclosures
The ServeRAID M5120 SAS/SATA Controller has the following specifications:
Eight external 6 Gbps SAS/SATA ports
Two external x4 mini-SAS connectors (SFF-8088)
Supports RAID levels 0, 1, and 10
Supports RAID levels 5 and 50 with optional M5100 Series RAID 5 upgrades
Supports RAID 6 and 60 with the optional M5100 Series RAID 6 Upgrade
Supports 512 MB battery-backed cache or 512 MB or 1 GB flash-backed cache
6 Gbps throughput per port
PCIe x8 Gen 3 host interface
Based on the LSI SAS2208 6 Gbps ROC controller
Supports connectivity to the EXP2512 and EXP2524 storage expansion enclosures
For more information, see the IBM Redbooks Product Guide 
ServeRAID M5120 SAS/SATA Controller for 
IBM System x
 at:
http://www.redbooks.ibm.com/abstracts/tips0858.html?Open 
The controllers support connectivity to the IBM System Storage external expansion enclosures listed in 
the following table. Up to nine expansion enclosures can be daisy-chained per one controller external 
port. For better performance, distribute expansion enclosures evenly across both controller ports.
Table 26. IBM System Storage external expansion enclosures
Part number Description Maximum quantity supported per 
one controller
174712X IBM System Storage EXP2512 Express 18
174724X IBM System Storage EXP2524 Express 9